So far, we discussed transforming a list by applying a function to the elements. In other words,map()andreplaceAll()take the function’s return values as the transformed elements. Next, let’s look at another scenario in which we call a function as performing an action and don’t care ab...
> sapply(1:8,z12) [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [1,] 1 2 3 4 5 6 7 8 [2,] 1 4 9 16 25 36 49 64 # sapply(x,f) applies the function f() to each element of x and then converts the result to a matrix 1. 2. 3. 4. 5. 6. 7. 8. 9...
The apply() function can be feed with many functions to perform redundant application on a collection of object (data frame, list, vector, etc.). The purpose of apply() is primarily to avoid explicit uses of loop constructs.apply函数的重要作用就是把一个函数给一群数据应用上，这个一群数据可...
data <- list(l1 = c(1, 2, 3, 4)) # apply the 'sum' function on data: sum_sapply1 <- sapply(data, sum) #output sum_sapply1 使用lapply查看输出的差异: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 sum_lapply1 <- lapply(data, sum) sum_lapply1 场景2:每个元素的长度>1且相同...
testf <- function(i){ covmatrix[[i]][apply(!is.na(covmatrix[[i]]),2,any),apply(!is.na(covmatrix[[i]]),2,any)] } newlist <- lapply(covmatrix, testf) 我得到错误代码:Error in covmatrix[[i]] : no such Index at Level 1我想我不能正确理解lapply是如何工作的。发布...
Returns a vector or array or list of values obtained by applying a function to margins of an ...
1、用途:对多个变量同时使用函数进行计算——Apply a Function to Multiple List or Vector Arguments 2、选项参数 1 mapply(FUN, ..., MoreArgs =NULL, SIMPLIFY =TRUE, USE.NAMES =TRUE) 1 2 3 4 5 >mapply(length,data) 水资源一级区 水资源二级区 水资源三级区 省级行政区 地级行政区 县级行政区...
Apply a Function Over Values in an Environment 对环境中的值使用函数 eapply(env, FUN, ..., all.names = FALSE, USE.NAMES = TRUE) mapply Apply a Function to Multiple List or Vector Arguments 对多个列表或者向量参数使用函数 mapply(FUN, ..., MoreArgs = NULL, SIMPLIFY = TRUE, USE.NAMES ...
sapply() 输入为 list, vector or data.frame ,输出为 vector or matrix. sapply()与 lapply() 可以完成相同的工作,但是输出的格式不一样。 sapply(X, FUN) Arguments: -X: A vector or an object -FUN: Function applied to each element of x ...
This MATLAB function applies a function func to each element of a gpuArray A and then concatenates the outputs from func into output gpuArray B.